Alloy



Patented 1 7,1925.

PATENT, oFFic ADOLPH Contact ew YORK, N. Y.

ALI-mt:

1T0 Drawing.

To all whom it may concern-.-

Be it known that I, ADoLrH CoHN, a citizen of the United States, and a resident of'New York city, county and State of New York, have invented certain new and useful Improvements in Alloys, of which the following is a specification.

, This invention relates to alloys of precious metals and particularly to alloys of platinum and its object is to alloy new and useful combinations of metals for the purpose of increasing hardness, improving physical characteristics and to provide for manufacturing. purposes, alloys of platinum which are-both better and cheaper than those available heretofore. More specifically, the object of this invention is to use ruthenium with platinum either alone or with platinum alloys containing iridium or palladium or gold or either.

These and other objects which are attained will appear in the following specification in which I will describe my invention, the novel features of which will be set forth in appended claims. v

Platinum is too soft to be suitable for use in jewelry and other manufactured articles and it is customary to add iridium or gold in desired amount to increase its hardness. Alloys are used .with the iridium content from a fraction of one per cent up to 33 of the whole. This method increases the-cost and has other objectionable features. .It is also customary to alloy palladium with platinum for the purpose of providing an alloy which is less expensive than platinum and while this does not materially affect the appearance, neitherdoes it materially increase the'hardness. It is common to add 20% to palladium to the platinum and the proportion of palladium used is sometimes as high as of the whole.

I have discovered that a small amount of ruthenium added to platinum-or to alloys of platinum with either iridium or palladium or gold has a very desirable effect. These metals form an alloy which will not tarnish or corrode, has suflicient ductility and malleability to be wrought either cold or hot, and is also capable of being melted and worked repeatedly without destroying its character. y r

I I have found that a decided hardening of platinum may be obtained by the addition of ruthenium is not lower than that of Application filed February 26, 1923. Serial No. 621,470.

of as little as one 'half of 1% ruthenium While I do not intend to limit myself in this particular, but as illustrations of the use of my invention, I have found by scleroscope tests that-an alloy of 97% platinum and 3% ruthenium is equal in hardness to an alloy of 90% platinum. and 10% iridium.

As iridium is more expensive than platinum 'or ruthenium, such an alloy is cheaper, and

furthermore'itis nearer pure platinum. It

is difiicult to make platinum and iridium allo s when the iridium content is greater than 1Q% because of the high melting point of 1r1d1um, but although the melting point -find that to obtain the hardness of an alloy proportion of of platinum and 10% iridum, I can use 93 platinum, 5% iridium and 1 ruthenium. It is an approximate rule that for every part of iridium omitted, one third as much ruthenium can be substituted to give like results.

I have also found that ruthenium can be used with platinum-palladium alloys and that it has practically the same effect on them, whether or not they contain iridium, that it has on iridium alloys.

I believe I can get the different results desired by the use of from one-half 'of1% to 15% ruthenium either with platinum or with alloys. of platinum-iridium, platinumgold, platinum-palladium or platinum-palladium gold or platinum-palladium-iridium.

What I claim is:

1. A manufactured, alloy comprising principally platinum with ruthenium, with the ruthenium content from one half of 1% to pure platinum or on platinum-- to 15% of the whole ruthenium with the pro- 1 portion of rutheniumincreased when the proportion of iridium is decreased.

. 4. YA manufactured alloy comprising principally platinum, with minor fractions of iridium and ruthenium with 1% to 30% of the whole iridium and with one half of 1% to 15% of the whole ruthenium with the proportion of ruthenium increased when the I proportion of iridium is "decreased with palladium and ruthenium with the ruthenium content from one-half of 1% to 15% of the whole.

6. A manufactured alloy comprising principally platinum with minor fractions of palladium, iridium and ruthenium with the proportion of ruthenium increased when the proportion of iridium is decreased with about one-third as much increase of ruthenium substituted for 1 the decrease in the iridium.

In witness whereof, I have hereunto set myhand and seal this 24th day of February,

.ADOLPH (JOHN; 

